1. Field of the Invention
This invention relates to an optical deterioration-accelerating weather and optical resistance testing apparatus for use in testing the weather and optical resistances of various kinds of materials and products while highly accelerating the optical deterioration thereof.
2. Description of the Prior Art
A prior art testing apparatus of this kind will now be described with reference to FIG. 2. FIG. 2 is a sectional side elevation view of a conventional optical deterioration-accelerating weather resistance testing apparatus according to Japanese Industrial Standards. Referring to the drawing, reference numeral 1 denotes a testing vessel provided with a light source 2 in the central portion thereof. A sample rotating frame 3 is rotated around the light source 2 by a rotary shaft 10 of the frame 3. A blower 8 circulates air introduced into the testing vessel via an air regulator 21 and a duct 22.
When the temperature in the vessel has reached a predetermined level, which is regulated by a temperature regulator, due to the heat generated from the light source 2, a valve 21a in the air regulator 21 is shifted to the position indicated by 21b. Consequently, outside air is introduced into the testing vessel 1, and hot air is discharged from an air discharge port 19, to cool the interior of the vessel. Namely, the valve 21a in the air regulator 21 is opened and closed in accordance with a temperature set by the temperature regulator, to switch the air flow passage.
A sample 4 receives the optical radiant energy from the light source 2, and the temperature of the sample increases due to the temperature in the testing vessel and the radiant energy, the sample 4 being deteriorated with the lapse of the test time. The distance between the light source 2 in the testing apparatus and the surface of the sample is 480 mm.
The testing temperature is measured with a black panel thermometer 9a (made by attaching a temperature measuring body close to a stainless steel plate of 150 mm in length, 70 mm in width and 1 mm in thickness, and coating the plate with black enamel) disposed adjacent the sample 4, and this temperature is suitably restricted.
An optical deterioration-accelerating weather and optical resistance testing apparatus is used to test the weather and optical resistance of various kinds of materials and products. The temperature and humidity of the air around and the quality of light applied to a sample constitute the important requisites for conducting tests and are required to be controlled stably for a long period of time.
In an optical deterioration-accelerating weather and optical resistance testing apparatus, a sample receives radiation from a light source, and the temperature of the sample thereby increases. For example, in a sunshine carbon arc light type optical deterioration-accelerating weather resistance testing apparatus, test conditions were determined as follows:
(a) Temperature of the surface of a sample measured with a black panel thermometer: 63.degree..+-.3.degree. C. or 83.degree..+-.3.degree. C. PA1 (b) Illuminance of radiation of the surface of a sample: 255+45 w/m.sup.2
However, regarding automobile parts, the optical deterioration-accelerating weather resistance tests have recently been conducted in more strict conformity with actual circumstances, i.e., the tests have been conducted at a temperature measured with a black panel thermometer of 80.degree.-100.degree. C. which is higher than a corresponding temperature used in similar tests before.
It has become necessary in recent years to require that materials and parts have a guaranteed life of 5-10 years, and, accordingly, the quality of materials has been improved year by year. The weather resistance of each material has also been very much improved. In conformity with such circumstances, as much as 1000 hours and not less than 2000 hours have recently been required in conducting tests for determining the weather resistance of material, whereas only about 500 hours were required before in conducting similar tests. In the current highly competitive technical world in which the testing techniques rapidly advance, a conventional testing apparatus of this kind cannot cope with the speed of development of materials and parts and the necessity to reduce test time for the determination of the weather resistance of the materials and parts.
Therefore, there has been a demand for a testing apparatus having excellent characteristics correlative with the outdoor exposure of a sample as in a conventional testing apparatus of this kind, and an optical deteriorating effect far superior to that of a conventional testing apparatus of this kind.